What is the limit of a mechanical fuel pump?
#880276
12/14/10 10:15 PM
12/14/10 10:15 PM
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Joined: Jan 2003
Posts: 1,221 Jarrettsville, MD
tywebb2
OP
super gas
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OP
super gas
Joined: Jan 2003
Posts: 1,221
Jarrettsville, MD
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Is there an E.T. cut off where say anything faster than a given time would signal that you should install an electric pusher type fuel pump in place of a traditional mechanical pump?
'72 440 Cuda 11.673 @ 115.91 w/1.663 60'
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Re: What is the limit of a mechanical fuel pump?
[Re: tywebb2]
#880277
12/14/10 11:25 PM
12/14/10 11:25 PM
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Joined: Feb 2004
Posts: 6,257 acworth / N. georgia - south e...
cheapstreetdustr
master
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master
Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
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most roundy round cars are required to run a mechanical fuel pump...so there are some heafty pumps that support alot of hp... they are rebuildable and tuneable. cheapst
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: What is the limit of a mechanical fuel pump?
[Re: tywebb2]
#880278
12/14/10 11:26 PM
12/14/10 11:26 PM
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Joined: Aug 2003
Posts: 43,230 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,230
Bend,OR USA
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My old M.W. stocker went 11:20s ET at 3550 Lbs. at 119.+MPH with a mechanical pump only and a piece of crap stuck in the fuel tank pickup that I didn't know about until after I sold it. There was other M.W. stockers at the same race that went 124 MPH using the mechanical pump with a Holley blue as a pusher pump in the back My car ran faster with the mechanical pump only versus using the Holley as a pusher hook up to the mechanical The pumps we used back then where the Hemi Carter NASCAR race pumps, they have three diaphrams in them instead of the standard two diaphrams
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: What is the limit of a mechanical fuel pump?
[Re: Cab_Burge]
#880279
12/15/10 12:09 AM
12/15/10 12:09 AM
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Joined: Jan 2003
Posts: 1,221 Jarrettsville, MD
tywebb2
OP
super gas
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OP
super gas
Joined: Jan 2003
Posts: 1,221
Jarrettsville, MD
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I guess I will be ok with my Carter street/strip mech pump and 3/8 line up to 11.5 then.....right?
'72 440 Cuda 11.673 @ 115.91 w/1.663 60'
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Re: What is the limit of a mechanical fuel pump?
[Re: tywebb2]
#880282
12/15/10 01:00 PM
12/15/10 01:00 PM
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Joined: Jan 2003
Posts: 13,375 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,375
Marion, South Carolina [><]
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Back when my car ran 11.40s at 117 mph, I was running a Carter strip pump mechanical pump and the factory 3/8" line. I "upgraded" to -8 line, put a sump in the tank, and got a Holley blue pump. Did not change the performance at all.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: What is the limit of a mechanical fuel pump?
[Re: tywebb2]
#880284
12/15/10 02:21 PM
12/15/10 02:21 PM
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Joined: Feb 2007
Posts: 5,080 organ
maximum entropy
master
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master
Joined: Feb 2007
Posts: 5,080
organ
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put a fuel pressure gauge in it, and then you'll know. i have a carter strip mechanical pump, 3/8 line, in a high ten second street car. the pressure is 6.5 at launch, and 6.5 at the stripe. i get the feeling i'm not even close to needing more.
for what is the good life if not doing things thoughtfully?
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Re: What is the limit of a mechanical fuel pump?
[Re: maximum entropy]
#880285
12/15/10 02:54 PM
12/15/10 02:54 PM
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Joined: May 2008
Posts: 1,238 North Cackilacky
sdaurity
pro stock
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pro stock
Joined: May 2008
Posts: 1,238
North Cackilacky
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A customer I just build an engine for Has a 500" lowdeck, car weighs 3800lbs and the other week I went 6.80 @ 102 in it, and it has a stock fuel pump he would not change it even with me on him about it. Didn't miss or anything, actually kind of surprised me by far the fastest I have seen a stock pump go.
One day I will have something cool here.
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Re: What is the limit of a mechanical fuel pump?
[Re: Sport440]
#880293
12/15/10 11:16 PM
12/15/10 11:16 PM
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Joined: Jan 2003
Posts: 1,221 Jarrettsville, MD
tywebb2
OP
super gas
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OP
super gas
Joined: Jan 2003
Posts: 1,221
Jarrettsville, MD
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Thanks for all of the feedback everyone. Based on most are saying I should be fine but I guess it would be nice to have a gauge viewable from the cockpit to see what the pressure is at the stripe. I would need an electric gauge with a sending unit if I want to put it in the car.....right?
Sport440....I talked to ATI this week and they said my 8" vert is the tightest they make. I am going to put it in the car and make a few more passes with it in 2011 and see what happens.
'72 440 Cuda 11.673 @ 115.91 w/1.663 60'
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Re: What is the limit of a mechanical fuel pump?
[Re: tywebb2]
#880294
12/15/10 11:51 PM
12/15/10 11:51 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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A mech fuel pump is pretty simple... diaphragm, inlet, outlet check valves and the pressure spring, then the actuator arm... the diameter and stroke of the diaphragm determine the volume... but the inlet and outlet check valves are the restriction in the pump. Some companies run 2 inlets and 2 outlet checks to move more fuel with the big diaphragms... the pressure spring on the back of the diaphragm will determine the pressure based on the restriction of the needle and seat.... I flowed a few thousand warranty pumps for Chrysler in the fuel lab and tore many apart to determine what the failures were
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Re: What is the limit of a mechanical fuel pump?
[Re: tywebb2]
#880295
12/16/10 03:32 PM
12/16/10 03:32 PM
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Joined: Aug 2003
Posts: 43,230 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,230
Bend,OR USA
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I found out the hard way that some electric tachs are not accurate, even high dollar race tachs Some of todays and some of the old race ignitions mess eletric tachs up above a certian RPM which may make your finish line RPM reading off so it looks like the converter is no good
Last edited by Cab_Burge; 12/16/10 05:12 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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